• 제목/요약/키워드: Domain switching

검색결과 178건 처리시간 0.04초

Nanoscale Probing of Ferroelectric Domain Switching Using Piezoresponse Force Microscopy

  • Yang, Sang Mo;Kim, Yunseok
    • 한국세라믹학회지
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    • 제56권4호
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    • pp.340-349
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    • 2019
  • In ferroelectric materials, piezoresponse force microscopy (PFM) has been widely used to explore ferroelectric domain switching. In this article, we review the fundamentals of nanoscale probing of ferroelectric domain switching using PFM, including the basic principles of PFM and a variety of PFM studies on local domain switching. We also introduce advanced PFM techniques for exploring switching behavior. Finally, we discuss several issues and perspectives in nanoscale probing of ferroelectric domain switching using PFM. PFM has played an important role in exploring switching behavior in ferroelectric materials, and it could be further developed to probe more detailed switching information.

(Pb,La)$TiO_3$ 강유전체 세라믹에서 분역반전과 Acoustic Emission의 관계 (The Relationship between Domain Switching and Acoustic Emission in (Pb,La)$TiO_3$ Ferroelectric Ceramacs)

  • 최동구;최시경
    • 한국세라믹학회지
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    • 제33권6호
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    • pp.672-678
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    • 1996
  • The relationship between domain switching and acoustic emission (AE) during poling was investigated using the tetragonal ferroelectric ceramics with composition of (Pb,La)TiO3+0.01MnO2 The amount of AE generation during poling increased with increasing dc electric field and raising temperature. It was confirmed that the change of the amount of AE generation with poling condition resulted from the difference of the amount of 90$^{\circ}$ domain switching and total amount of AE generation for 10 minutes was approximately proportional to the amount of 90$^{\circ}$domain switching. The A generations of two specimens which have different tetragonality rations(c/s rations) 15 at% and 24at% La-doped were also investigated. The sample with c/a ratio of 1.012 where 90$^{\circ}$ domains are dominate had larger amount of AE generation and 90$^{\circ}$ domain switching compared with the sample with c/a ratio of 1.004 where 180$^{\circ}$ domains are dominant.

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Domain Switching and Crack Propagation of $BaTiO_3$ Single Crystal in Different Environments

  • Gao, Kewei;Zhao, Xianwu;Wang, Ruimin;Qiao, Lijie;Chu, Wuyang
    • Corrosion Science and Technology
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    • 제7권6호
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    • pp.307-314
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    • 2008
  • The influence of a moist atmosphere on $90^{\circ}$ domain switching under a sustained electric field, stress corrosion cracking of an indentation crack in water and an aggressive solution, and the relation between penetrating crack propagation and domain switching were studied using $BaTiO_3$ single crystal. The results indicate that enlarging the domain switching zone and crack propagation could be facilitated by a moist atmosphere or an aggressive solution due to the indentation residual stress. A moist atmosphere exerts remarkable influence upon the polarization of $BaTiO_3$ single crystal under a sustained electric field, and the surface energy of the c domain was much lower than that of the a domain. Domain switching ahead of a penetrating indentation crack tip was an essential requirement for crack propagation under constant stress.

분역회전이 강유전체 세라믹내의 균열성장에 미치는 영향 (Effect of Domain Switching on Crack Growth in Ferroelectric Ceramics)

  • 정경문;박재연;범현규
    • 한국정밀공학회지
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    • 제20권11호
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    • pp.142-149
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    • 2003
  • Domain switching effect on crack growth in ferroelectric ceramics under combined electric and mechanical loading is investigated. The shape and size of the switching zone is shown to depend strongly on the relative magnitude between the applied electric field and stress field as well as on the ratio of the coercive electric field to the yield electric field. The toughening mechanism is thought to be ferroelectric domain switching leading to the development of a process zone around the crack. Crack-tip stress intensity factor induced by domain switching for the steady state crack growth is numerically obtained.

주사 힘 현미경에 의한 (001) Pb(Mg1/3Nb2/3)O3-x%PbTiO3 단결정의 도메인 구조 및 분극 스위칭 관찰 (Observation of Domain Structure and Polarization Switching in (001)-oriented Pb(Mg1/3Nb2/3)O3-x%PbTiO3 Single Crystals by Scanning Force Microscope)

  • 이은구
    • 한국세라믹학회지
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    • 제47권4호
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    • pp.333-337
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    • 2010
  • Domain structure and polarization switching in (001)-oriented $Pb(Mg_{1/3}Nb_{2/3})O_3-x%PbTiO_3$ (PMN-x%PT) crystals for x=20 and 35at% have been investigated in-situ by scanning force microscope (SFM) in a piezoresponse mode under a step DC electrical voltage. In the initial annealed condition, polar nano domains (PND) and domain striations oriented along {110} were observed in x=20 and x=35, respectively. For x=20, domain switching occurs by heterogeneous nucleation, where nucleation is not confined in the vicinity of domain boundaries, but rather can occur throughout the crystal volume. However, for x=35, domain switching tends to be preferentially initiated near pre-existing twin boundaries. With increasing the applying voltage, the nuclei density increased and assembled into {110} striations, indicating a stress-accommodated domain growth process. At higher voltage, nucleation occurs heterogeneously throughout the crystal volume.

Switching current density for spin transfer torque magnetic random access memory with Dzaloshinskii-Moriya Interaction

  • Song, Kyungmi;Lee, Kyung-Jin
    • 한국자기학회:학술대회 개요집
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    • 한국자기학회 2015년도 임시총회 및 하계학술연구발표회
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    • pp.78-79
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    • 2015
  • We investigate the switching current for various cell diameters and DM interaction. We find that the current density for switching can depend strongly on the cell size when the switching is governed by the domain wall motion. Moreover the switching current density is also strongly influenced by DM interaction. In the presentation, we will discuss the effect of domain wall formation and more various DMI constant on the switching current desity in detail.

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A Novel Fast-Switching LCD with Dual-Domain Bend Mode

  • Satake, Tetsuya;Kurata, Tetsuyuki
    • Journal of Information Display
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    • 제5권2호
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    • pp.39-42
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    • 2004
  • A novel fast-switching LCD with dual-domain bend (DDB) mode is described. DDB alignment is achieved using antiparallel-rubbed cell filled with chiral-doped LC. Initial alignment is mono-domain 180-degree twist. Tilt direction is controlled by oblique electric field to be counter direction in each domain. Twist-to-DDB deformation occurs continuously so that DDB mode does not require high-voltage initialization which is inevitable in Optically Compen sated Bend (OCB) mode. DDB gives wide and symmetric viewing angle in contrast to mono-domain bend formed from 180-degree twist showing strong asymmetry.

분역회전이 강유전체 세라믹 액추에이터 내의 균열발생에 미치는 영향 (Effect of Domain Switching on Cracking in Ferroelectric Ceramic Actuators)

  • 정경문;김재연;범현규
    • 한국정밀공학회지
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    • 제22권2호
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    • pp.113-119
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    • 2005
  • A crack emanating from an internal electrode or a conducting damage path in ferroelectric ceramic actuators is analyzed. The boundary of the domain switching zone near the edge of the internal electrode in a ceramic multilayer actuator is determined based on the nonlinear electric theory. The stress intensity factor induced by a ferroelectric domain switching under small scale conditions is numerically obtained for flaws of various sizes near the electrode edge. It is found that stress intensity factor near the crack tip depends on the material property of the electrical nonlinearity.

Effects of Grain Boundaries on Photovoltaic Current and Photoinduced Domain Switching in Ferroelectric Ceramics

  • Kim, Sung-Ryul;Choi, Dong-Gu;Choi, Si-Kyung
    • The Korean Journal of Ceramics
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    • 제6권3호
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    • pp.262-266
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    • 2000
  • We investigated the effect of the grain size on the photovoltaic current in (Pb$_{1-x}$La$_x$)TiO$_3$ceramics, and the photoinduced domain switching in (Pb$_{0.85}$La$_{0.15}$)TiO$_3$and BaTiO$_3$ceramics. These behaviors in ferroelectric ceramics were attributed to the grain boundary at which photoexcited electrons were trapped. As the charged grain boundary acted as an electro-potential barrier which impeded the movement of electrons, the photovoltaic current showed a peak at a critical grain size. The space charge field built by the electrons trapped at the grain bound-aries was accounted for the photoinduced domain switching, and AE experimental results support well this account.

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A Novel Fast-Switching LCD with Dual-Domain Bend Mode

  • Satake, Tetsuya;Kurata, Tetsuyuki
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.209-212
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    • 2004
  • A navel fast-switching LCD with dual-domain bend (DDB) mode is described DDB alignment is achieved using antiparallel-rubbed cell filled with chiral-doped LC. Initial alignment is mono-domain 180-degree twist. Tilt direction is controlled by oblique electric field to be counter direction in each domain Twist-to-DDB deformation occurs continuously so that DDB mode does not require high-voltage initialization which is inevitable in Optically Compensated Bend (OCB) mode. DDB gives wide and symmetric viewing angle in contrast to mono-domain bend formed from 180-degree twist showing strong asymmetry.

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